A Registered Dietitian who has a strong personal interest in sport nutrition committed to helping people eat well and lead a healthy lifestyle. She believes adequate nutrition plays an essential role in the health, well-being and performance of athletes.

Ulaine Nel

Registered Dietitian

About Ulaine Nel

Ulaine is a Registered Dietitian who has a strong personal interest in sport nutrition committed to helping people eat well and lead a healthy lifestyle.

She believes adequate nutrition plays an essential role in the health, well-being and performance of athletes. She is also passionate about a wholefoods plant based diet approached with the focus on a variety of nutrient dense food sources and consider this the best fuel for active individuals and for the treatment and prevention of chronic diseases of lifestyle. Ulaine qualified with a BSc in Dietetics degree from Stellenbosch University on 2013 after which she completed her Community Service year in Zastron – a small rural town in the Free-State. Her focus there was community nutrition combined with clinical nutrition and food service management.

She also commenced with her Master’s degree in Nutrition during the same year, focussing mainly on sport nutrition for her research. In June 2013, she started following a plant-based lifestyle after research on the health and environmental benefits this lifestyle offers. She experienced an overall health transformation and improved quality of life and has never looked back. You will find her as someone who is always encouraging people to adopt healthier eating habits so that they are at the peak of their mental and physical ability.

Importance of enough energy:

The correct nutrition is essential to support the abovementioned energy systems used in CrossFit. To optimize training adaptions and performance, it is important for athletes to consume enough calories to compensate for the energy expended during exercise.

It is evident that when overall energy requirements aren’t met it may hinder training and performance by causing a loss of muscle mass and strength. Athletes may also be more susceptible to illness as well as have an increased chance of chronic fatigue or burnout.

If more energy is expended relative to energy intake, it compromises exercise performance and negates the benefits of training. The body is adapted to use lean tissue mass as an energy source when energy intake is limited. This will result in a loss of strength and endurance as well as a compromised musculoskeletal, endocrine and immune function as well as an increased prevalence of overtraining syndrome. Furthermore, nutrient deficiencies and a lowered resting metabolic rate (RMR) will result from a chronic low energy intake due to a poor nutrient intake especially micronutrients.

As mentioned above, inadequate energy intake is not recommended as it causes various negative health effects. Therefore, it is very important to make sure athletes have enough estimated energy availability that is suited for the amount of energy they expend.

The three energy systems:

ATP-CP System:This non-oxidative type of system is used for short intense bursts of energy such as short sprint efforts used in CrossFit such as the 40m sprint. The main fuel source used is ATP (Adenosine Triphosphate).

Lactate System: This system is also not depended on oxygen and is usually activated after the ATP-CP system is used up.

The main energy fuel source is therefore muscle glycogen which leads to the breakdown of glycogen. An accumulation of lactate in the muscles is a result of the glycogen breakdown causing fatigue. This system is generally used when training for Tabata squads or a 500m row.

Aerobic System:Unlike the other two systems, this system uses oxygen to produce energy by the breakdown of carbohydrates, fat and ultimately protein. This system is used for endurance type exercises such as a 5km Run that is more moderate to low intensity for longer periods of time.

Energy systems used in CrossFit & Nutrition

Generally, when you are training, your body will use three distinct energy systems. These systems are important for energy production and knowing how they work can help you progress faster by tailoring your nutrition and energy requirements to support these systems.

You can distinguish between the systems by the type of resources it uses for energy production. An Anaerobic system (non-oxidative) does not need oxygen to produce energy whereas an Aerobic (Oxidative) system uses oxygen to aid energy production.